1. Field of the Invention
The present invention relates to a pneumatic dispensing gun, and more particularly to a pneumatic dispensing gun including an adjusting or pressure regulating device for regulating the pneumatic pressure and for suitably or adjustably dispensing the flowable materials from the prefilled packages or cartridges.
2. Description of the Prior Art
Typical dispensing guns or caulk guns or extrusion devices comprise a C-shaped frame or a receptacle attached to a gun body for receiving a prefilled package or cartridge therein, and a push rod engageable into the prefilled package or cartridge, and an actuating or driving handle coupled to the push rod for applying a force to dispense or to distribute the flowable materials from the prefilled packages or cartridges.
For example, U.S. Pat. No. 5,156,305 to Eyre, and U.S. Pat. No. 5,626,263 to Lii disclose two of the typical caulk dispensing guns or C-clamp assemblies and each also including a receptacle or cartridge keep attached to or extended from a gun body or stock for receiving a prefilled package or cartridge therein, and an actuating or driving handle coupled to a push rod which is engageable into the prefilled package or cartridge for forcing the push rod to dispense or to distribute the flowable materials from the prefilled packages or cartridges.
However, the users have to spend a great force to pull or to trigger the actuating or driving handle in order to dispense or to distribute the flowable materials from the prefilled packages or cartridges, such that the typical caulk dispensing guns are not good for long term working people.
U.S. Pat. No. 5,058,769 to Kurtz discloses another typical pneumatic caulk dispensing gun including a gun body member for receiving a prefilled package or cartridge therein, and a connector for coupling to a pressurized air supplier reservoir or a pressurized gas source for receiving the pressurized air or gas and for forcing or dispensing or distributing the flowable materials from the prefilled packages or cartridges.
However, the pressurized gas supplied from the pressurized air supplier reservoir or gas source may not be regulated or adjusted particularly when the pressurized air or gas is over-pressurized or when the pressurized air or gas is not stable or steady.
The present invention has arisen to mitigate and/or obviate the afore-described disadvantages of the conventional dispensing guns or devices for dispensing or distributing the flowable materials from the prefilled packages or cartridges.